Foamed shoe sole

ABSTRACT

A foamed sole body includes a front portion, a heel portion, an intermediate portion interconnecting the front, and heel portions, and a peripheral surface that surrounds the front, intermediate and heel portions and that interconnects top and bottom surfaces of the sole body. An outer covering layer is bonded to and covers entirely the peripheral surface of the sole body. Alternatively, the outer covering layer may cover not only to the bottom surface of the sole body but also the peripheral surface.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a shoe sole, and more particularly to a shoe sole that is made from a foam material.

2. Description of the Related Art

Conventional shoe soles, such as insoles, midsoles and outsoles, are fabricated by directly filling and forming a foam material , such as polyurethane, in a mold. However, when the foam material is used to make a low density foamed sole, multiple pores formed in the foamed soles will produce substantial surface irregularities and roughness which degrade the esthetic appearance of the formed sole. Therefore, additional processing steps are needed to remove the surface roughness from the foamed soles , which increases the manufacturing cost. Furthermore, because polyurethane foam has low resistance to abrasion and hydrolysis, shoe soles made therefrom are insufficient to provide good structural strength.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a foamed shoesole that has good appearance and high structural strength.

Accordingly, a shoe sole according to the present invention comprises a foamed sole body, and an outer covering layer. The foamed sole body has a front portion, a heel portion, an intermediate portion interconnecting the front and heel portions, and a peripheral surface surrounding the front, intermediate and heel portions. The front, intermediate and heel portions cooperatively define a top surface and a bottom surface. The peripheral surface interconnects the top and bottom surfaces. The outer covering layer is bonded to and covers entirely the peripheral surface of the sole body.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

FIG. 1 is a perspective view of a foamed shoe sole according to a preferred embodiment of the present invention;

FIG. 2 is a sectional view of the foamed shoe sole of FIG. 1; and

FIG. 3 is a sectional view of a foamed shoe sole according to another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail with reference to the accompanying preferred embodiments, it should be noted here in that like elements are denoted by the same reference numerals throughout the disclosure.

Referring to FIGS. 1 and 2, a foamed shoe sole according to a preferred embodiment of the present invention is shown as having a foamed sole body 2, and an outer covering layer 3. The shoe sole may be an insole, a midsole or an outsole of a shoe. In this embodiment, the foamed shoe sole is a midsole.

The foamed sole body 2 has a front portion 21, a heel portion 22, an intermediate portion 23, and a peripheral surface 24 surrounding the front, intermediate and heel portions 21, 23, 22. The front, intermediate and heel portion 21, 23, 22 cooperatively define a top surface 201 and a bottom surface 202. The peripheral surface 24 interconnects the top and bottom surfaces 201, 202. In this embodiment, the sole body 2 is made of polyurethane.

The outer covering layer 3 includes a thin sheet or film 34 that is bonded to and covers entirely the peripheral surface 24 of the foamed sole body 2. Preferably, the outer covering layer 3 is made from a high density thin sheet, or a thermoplastic blown film using a material selected from the group consisting of polyurethane, thermoplastic polyurethane or a combination thereof. The thickness of the outer covering layer 3 preferably ranges from 0.01 mm to 0.02 mm.

In fabrication, the material of the outer covering layer 3 is thermo-formed into a sheet or film that is not foamed, and is disposed on an inner surface of a mold cavity (not shown). Thereafter, a material of the sole body 2 is filled in the mold cavity to form the sole body 2 and to thermal bond the sole body 2 to the outer covering layer 3.

The outer covering layer 3 has a high density structure and is resistant to hydrolysis and wearing. Therefore, the foamed sole body 2 can be protected by the outer covering layer 3 from being hydrolyzed and abraded easily. Because the outer covering layer 3 and the foamed sole body 2 are made of the same or similar material (i.e. polyurethane, thermoplastic polyurethane), they are highly compatible and highly resistant to separation. The combination of the outer covering layer 3 and the foamed sole body 2 exhibits excellent tensile strength that increases the supporting properties of the shoe sole. In addition, because the outer covering layer 3 is a thin sheet or a blown film that provides the sole body 2 with a smooth and waterproof outer surface, further processing of the sole body 2 is unnecessary. Moreover, the smooth outer surface thereof may be colored easily.

Referring to FIG. 3, a shoe sole according to another preferred embodiment of the present invention is configured as an outsole which also includes a foamed sole body 2 and an outer covering layer 3. However, the outer covering layer 3 is bonded not only to the bottom surface 202 of the sole body 2 but also to the peripheral surface 24 of the sole body 2.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A shoe sole comprising: a foamed sole body having a front portion, a heel portion, an intermediate portion interconnecting said front and heel portions, and a peripheral surface surrounding said front, intermediate and heel portions, said front, intermediate and heel portions cooperatively defining a top surface and a bottom surface, said peripheral surface interconnecting said top and bottom surfaces; and an outer covering layer bonded to and covering entirely said peripheral surface of said sole body.
 2. The shoe sole of claim 1, wherein said outer covering layer has a thickness ranging from 0.01 mm to 0.2 mm.
 3. The shoe sole of claim 2, wherein said outer covering layer is a film that is not foamed.
 4. The shoe sole of claim 3, wherein said outer covering layer is made of a material selected from a group consisting of thermosetting polyurethane, and thermoplastic polyurethane.
 5. The shoe sole of claim 1, wherein said outer covering layer further covers said bottom surface of said sole body. 